He warned: “If you don’t evacuate, you are not only endangering your life, you are also endangering the lives of the first responders who are going in to rescue you.”

Londoner Divya Samtani, 22, who lives in New York, said: “Everyone is freaking out. Flashlights are sold out everywhere, queues are really long in the supermarkets and all the hardware shops are closed.

“We’re all kind of hanging in there and waiting. I’m working from home because all the transport is shut and no one can get to work.”

Novelist Philip Hensher, 47, originally from Sheffield but who lives in Manhattan, said: “We’re up on the 29th floor and the wind is brisk but not terrifying. The sky looks very black.”

British Airways and Virgin Atlantic yesterday cancelled dozens of flights between London Heathrow and East Coast cities including New York, Baltimore, Washington, Boston and Philadelphia.

Almost 7,500 flights were cancelled globally, said the flight-tracking service FlightAware. At Heathrow, hundreds of Britons arrived home yesterday after catching the last flights out of New York.

“There was a lot of panic in the city and the atmosphere was quite scary.”

Some New Yorkers were unable to get home. Veronica Bridi, 40, was told she may not now get a flight until Thursday.

She said: “My 10-year-old daughter’s school has closed. I spoke to her on the phone.

“She said she wants me home because she’s scared.”

British rock band Asia has been forced to cancel two shows in Annapolis, Maryland. Sound engineer Steve Rispin said the group had been forced to take refuge in a hotel.

He said: “There has been extremely heavy rain and it has been very windy, the venue was forced to cancel two of the band’s shows on Sunday and Monday.”

The Caerphilly schoolchildren are staying at the Marriott Courtyard in Lyndhurst, New Jersey.

History teacher Matthew Ferris said: “It’s a real shame but we have to put safety first.

“We have ordered in some pizza and they are making trips to the deli over the road where they serve those massive American-style sandwiches.”

Last night US coastguards were involved in a desperate search for two crew still missing at sea after abandoning the replica ship HMS Bounty off North Carolina.

The captain and a crew member were believed to be wearing survival suits but were still adrift.

The 180ft three-masted ship was built for the 1962 film Mutiny On The Bounty with Marlon Brando and had appeared in Pirates Of The Caribbean II.

It sunk 90 miles off the coast after being battered by 20ft waves and ferocious gales.

And in the Dominican Republic coastguards are still searching for seven people who disappeared from a rigid-hulled inflatable boat caught in the storm on Sunday.

Stephen Davenport, senior meteorologist at MeteoGroup, warned of trees collapsing in the high winds and probable power cuts, but said it was possible Sandy could lose some of its power when it comes inland.

The storm has already killed 66 people in the past week as it swept through the Caribbean.